Sliding wing dies

ABSTRACT

A vertical press tube bender has wing dies which are mounted on wing die supports for relative movement with respect to the supports so that the wing die position is controlled by movement of the tube during bending.

United States Patent 91 Johnston Apr. 17, 1973 SLIDING WING DIES 2,456,675 12/1948 Chaille ..72/396 2,887,141 5/1959 Bower [75] Inventor. James H. Johnston, Jackson, MlCh. 3,306,093 2H9 sassak u [73] Assignee: Tennec o Inc., Racine, Wis. 3,552,179 1 1971 Kapustin ..72/3s9 22 F1 1 led Nov 1970 Primary Examiner-Charles W. Lanham [21] App 90,4 Assistant Examiner-Gene P. Crosby Attorney-Harness, Dickey & Pierce [52] US. Cl ..72/389, 72/396 [51] Int. Cl. ..B2ld 7/00 ABSTRACT [58] Fleld of Search 385, A vertical press tube bender has g dies which are 72,386 382 mounted on wing die supports for relative movement with respect to the supports so that the wing die posi- [56] References Clted tion is controlled by movement of the tube during UNITED STATES PATENTS bendmg 1,948,474 2/1934 4 Claims, 12 Drawing Figures Meyer .72/396 SLIDING WING DIES BRIEF SUMMARY OF THE INVENTION It is the purpose of the invention to reduce the forces applied by the wing dies to a tube (or other part) during bending thereby minimizing thinning of the tube being bent as well as other distortions, such as flattening or collapse. This purpose is accomplished by means of a wing die structure which provides for relative movement between the wing dies and the wing die supports so that the, wing dies can move with the tube being bent.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view, partly schematic and partly broken away, of a vertical compression tube bender having wing die means constructed in accordance with the invention showing the bender in the bend position;

FIG. 2 is a view of the bending die and the wing die parts of this invention at a 90 bend position;

FIG. 3 is a view similar to FIG. 2 but showing the parts in the 160 bend position;

FIG. 4 is a detail side elevation ofa wing die holder; FIG. 5 is a side elevation taken from the right of FIG.

FIG. 6 is an end elevation of the wing die used on the left side of FIGS. 1 to 3;

FIG. 7 is an end elevation of the wing die section used on the right of FIGS. 1 and 3;

FIG. 8 is a plan view of the wing die shown in FIG. 7;

FIG. 9 is an end elevation ofa second section of wing die used on the right sides of FIGS. 1 to 3;

FIG. 10 is a plan view of the wing die shown in FIG.

FIG. 11 is a side elevation of a connector used between the wing die section of FIG. 8 and the wing die section of FIG. 10; and

FIG. 12 is an end elevation showing a wing die mounted in a wing die holder to reveal the clearances that permit a substantial degree of self-alignment of the wing die with the tube being bent. 1

DESCRIPTION OF THE INVENTION The vertical compression tube bender 1 has vertically extending ways 3 which guide and support a vertically moving ram 5 on the bottom end of which is attached a bending die 7. The die 7 has a semi-circular bottom face 9 which contains a substantially semi-circular cross section channel 11 sized to receive the tube 13 which is to be bent in the machine 1. Supported as a part of the machine 1 in operative alignment with the bending die 9 are a pair of wing die supports 15 and I7 which can pivot around axis 19 and 21, the wing dies 15 and 17 being mounted in a conventional manner and their axes of pivotal movement being adjustable to ac commodate different tubes and different bends.

The wing die supports 15 and 17 include ledges 23 and 25 that provide upwardly facing surfaces 27 and 29 on which the wing die means 31 and 33 incorporating the present invention are mounted. The left wing die means 31 includes a wing die holder 37 and the right wing die means 33 includes the wing die holder 39. The wing die holders contain suitable apertures 34 (FIG. 4) to receive bolts 35 whereby they are fixed in position on the wing die supports 15 and 17 to move in predetermined paths prescribed by the structure of machine 1.

The left wing die means 31 has a wing die member 41 which is movably supported on the wing die holder 37 and which contains a substantially semi-circular channel 43 that receives the tubing 13. The right wing die means 33 has a two-piece wing die member-comprising wing die member section 45 and wing die member section 47. These are movably mounted on the wing die holder 39 and have aligned substantially semi-circular channels 49 and 51 that receive the tubing 13. The wing die members 41, 45, and 47 can slide lengthwise on the respective wing die holders 37 and 39 so that, as seen in FIGS. 2 and 3, there is relative movement between the wing die members and holders as the tube 13 is bent. During bending, friction between the wing die members and the tube 13 is high and will tend to inhibit relative movement between the members and tubing and such restriction of movement is accommodated by sliding of the wing die members on the holders.

The wing die holder 39 is shown in detail in FIGS. 4 and 5 and it will be understood that wing die holder 37 is simply the reverse or lefthand construction so that the same reference numbers may be used hereinafter in descriptions involving either one.

In the embodiment of the wing die holder illustrated there is a base member 55 which has a bottom face 57 and side rails 59 which include elevated side rail sections 61. A pair of separated wear plates 63 extend between the rails 59 and are secured by counter-sunk screws 65 to the bottom section 57. Hold-down plates 67 are attached by cap screws 69 in position on top of the elevated rail sections 61 and have overhanging portions 71 that act with the surface of the wear plate 63 and with faces of the rails 61 to define reentrant grooves or vertical ways 73. Running the fulllength of the bottom 57 between plates 63 is a semi-circular channel 75 that serves as a bed and support for a spring as will be described.

Referring to FIG. 6, the sliding wing die member 41 comprises an elongated block that has a bottom face 75 and the aforementioned channel 43 which opens out of the top face 77. The vertical sides 79 of the block include grooves 81 which are shaped to receive as sliding keys the projecting edges 71 of the plates 67 on the wing die holder 37 while the bottom face 76 rests on the wear plate surface 63. As seen in FIG. 12, the grooves 81 are somewhat oversized with respect to the projections 71 and the width of the die holder between the faces 73 is somewhat greater than the width of the die member 41 between faces 79 so as to provide clearances 83. Thus, some shifting of the die member 41 relative to the holder can occur so that the die member can align itself with the tubing 13 during the course of bend. The clearances also accommodate any minor inaccuracies in the machining or assembling of the parts. The same relationships exist between the wing die sections 45 and 47 and the wing die 39.

Referring to FIGS. 7 and 8, the wing die member section 45 is substantially the same in cross section as the member 41 illustrated in FIG. 6 and therefore has a block 85 with a bottom face 87 and side faces 89 with grooves 91 to receive the flanges 71. Similarly, the wing die member section 47 of FIGS. 9 and 10 comprises a block 93 with a bottom face 95 and sides 97 having grooves 99 that will receive the flanges 71.

It has been noted that the lefthand wing die member 41 is of one-piece construction whereas the righthand wing die member comprises two distinct sections. This permits the section 47 to be removed in cases where there are two bends in tube 13 that are close together and enables support to be given by the section 45 without interference by the section 47. The sections 45 and 47 are held together by an L-shaped connecting piece 103 which is shown in FIG. 11 which has a base section 105 that is apertured at 106 to receive sunken screws that will secure it in place in a slot 107 formed in the bottom of the inner die member 45, the inner die member having threaded holes 109 aligned-with the holes in the member 103. At the righthand end of the link 103 is a vertical flange or lug 111 which fits in a transverse slot 113 that is formed in the bottom of the die member 47, the member 103 fitting in a slot 115 that serves as a continuation of slot 107 when the die members 45 and 47 are placed in end-to-end contact with each other. Thus, when section 47 is clear of keys 71 on the wing die holder 33 it can be simply lifted off the link piece 103 and removed from the holder.

Spring means are used to urge the wing die members and wing die hold'ers toward the zero bend position of FIG. 1. Thus, a coil spring 117 (FIG. 3), which fits in groove 75 of holder 37, is anchored at its inner end to the wing die 41 by a cap screw 119 which is threaded into hole 121 (FIG. 6) in the wing die and is anchored at its outer end to the holder 31 by a screw 123 that threads into hole 125. Similarly, on the right hand side, a coil spring 127, which tits in groove 75 of holder is anchored at its inner end to the wing die member section45 by a cap screw 129 that threads into hole 131 (FIG. 7) and is anchored at its outer end to the holder 33 by a screw 133'that threads into hole 125.

Stop means are provided to limit the relative movement of the wing die members and holders under the influence of springs 117 and 127. For this purpose the left wing die member 41 has a cross hole 134 (FIG. 6) adjacent its inner end extending between grooves 81 and, in a similar manner, the wing die member section 45 has a cross hole l35 between grooves 91. The opposite-ends of hole 134. receive press fit plugs 137 (FIG. 3) and the opposite ends of hole 135 receive pressfit plugs 139 which,.as seen in FIG. 1, engage the ends 141 (FIG. 4) of the plates 67 to define the zero bend position of the wing die members on the wing die holders.

In operation, after the tube 13 has been placed in the proper position in FIG. 1, the machine 1 is actuated to lower ram 5. Downward movement of bend die 7 spreads the wing die means 31 and 33 as seen in FIG. 2 and the wing die means act to wrap the tube 13 around the bend die as seen in' FIGS. 2 and 3. During this movement the wing die members can adjust themselves to the tube and to the holders by virtue of the clearances shown in FIG. 12 but this does not sacrifice tube support as furnished by grooves 43, 49, and 51.

the spirit and scope of the invention.

I c arm:

1. A vertical press-type tube bender comprising a frame having a ram supported for vertical reciprocating movement, a bend die mounted on the bottom 'end of the ram and having a groove shaped to engage a pipe being bent, a pair of wing die supports disposed beneath and on opposite sides of the bend die, a pair of wing diemeans mounted respectively on the wing die supports, said wing die means each including at least one wing die member, having a groove aligned with the groove in the bend die and cooperating therewith to grip a tube during bending, said wing die means including wing die holders mounted respectively on the wing die supports and having a sliding key connection with the wing die members, 'and spring means acting between the wing die members and wing die holders and urging the members'to a predetermined position with respect to the holders.

2. A bender as set forth in claim 1 wherein said predetermined position corresponds to the position before bending begins. i

3. A bender as set forth in claim 1 including clearance spaces in each said key connection providing for self alignment of the wing die members with respect to the part being bent. I

4. A bender-as set forth in claim 1 wherein one of the wing die members comprises a plurality of longitu- 

1. A vertical press-type tube bender comprising a frame having a ram supported for vertical reciprocating movement, a bend die mounted on the bottom end of the ram and having a groove shaped to engage a pipe being bent, a pair of wing die supports disposed beneath and on opposite sides of the bend die, a pair of wing die means mounted respectively on the wing die supports, said wing die means each including at least one wing die member having a groove aligned with the groove in the bend die and cooperating therewith to grip a tube during bending, said wing die means including wing die holders mounted respectively on the wing die supports and having a sliding key connection with the wing die members, and spring means acting between the wing die members and wing die holders and urging the members to a predetermined position with respect to the holders.
 2. A bender as set forth in claim 1 wherein said predetermined position corresponds to the position before bending begins.
 3. A bender as set forth in claim 1 including clearance spaces in each said key connection providing for self alignment of the wing die members with respect to the part being bent.
 4. A bender as set forth in claim 1 wherein one of the wing die members comprises a plurality of longitudinally separate sections. 